Spark-plug.



W. S.-THOMAS.

SPARK PLUG.

APPLICATION man AUG. 10. 1915.

Patented Apr. 10, 1917.. I

a "menace.

. I WILLIAM S. THOMAS, OF LOCK HAVEN, PENNSYLVANIA, ASSIGNOR 03h ONE-HALF T0 JAMES E. BUZZARD, 0F LOCK HAVEN, PENNSYLVANIZA.

To alt whom it may concern:

Be it known that 1, WILLIAM S. THOMAS,

tain new and useful Improvements in Spark- 1 Plugs, of which the following is a specifica- My invention consists of an improved form of spark plug and is especially serviceable for use in connection with internal combustion engines. One object of my invention is to produce a spark plug which will efiiciently protect its electrodes and adjacent elements from carbon deposit.

Another object is to so produce my i'm proved spark plug that it will be of simple construction and the several parts may be quickly and easily removed and assembled. A further object of my invention is to pre vent the electrodes from injury both while in action and during the assembling of the same.

Another object is to so construct my improved spark 'plug that it may be easily and cheaply manufactured. and can be adjusted to suit diiferen'tconditions and types of en gines.

These objects, and other advantageous ends which will be described hereinafter, I.

attain in the following manner, reference being had to the accompanying drawings in which- Figure l is' spark plug.

Fig. 2 is a section Fig. 1.

Fig. 3 is abottom on-the line 0-0; of

, plan view of Fig. 1. Fig. 4 is a fragmentary view'of a portion of my spark plug showing adiii'erent arrangement of holes than is shown in Figs. 1 to 3 inclusive.

Fig. 5 is an end view of Fig. & showing.

the shape and location of said holes.

eferring to body portion being externally screw-thread ed at 2' so as to fit a tapped opening in an internal combustion engine or the like.

The body -portion,1",i's internally screw threaded at'3 at itsfupperend, and is proin shoulder a which said body portion 1.

Specification of Letters Patent. Application filed August 10, 1918. Serial No;

an elevation of my improved the drawings, 1 is'a hollow.

to the action of gfor a jacket 5 which snugly fits within Borodin the interior of SPARK-PLUG.

Patented am. it) 191?. 314,133.

The jacket 5 is recessed at 7 and is provided with a hole 8 which intersects said recess and extends to the inner surface 9. The i ole 8 is of smaller diameterthan the "recess 7, so that an enlarged annular portion 0 of a porcelain l1 rests upon the shoulder 12 formed by the intersection of said hole ;8 with the recess 7.

The lower portion 13" of the porcelain 11 fits the hole 8, and the space between the upper portion 14 of the porcelain and the walls of the jacket forming the recess 7 is filled with cement as shown at 15.

A nut 16 has a depending threaded stem 17 which engages the internal screw-thread 13 of the body portion 1, and the lowermost portion of said stem 17 engages the upper surface 18 of the jacket 5. .lhe nut 16 has a hole 19 of larger diameter than the upper portion of the porcelain 11, so that while the stem portion Tl?- of the nut 16 engages the upper rface 3.8 of the jacket 5, the'nut will be entirely free of the porcelain 11, so that he electrode 20 is located adjacent an adjustable electrode 23,,tl1e latter being secured to a screw 2-1 which fits within a tapped opening in the lower part '26 of the body portion -1. A chamber 2? is thus provided and the chamber 526 communicates with the upper surface of the body portion 1 through the medium tions 29; i

llhese perforations29 are substantially elliptical and taper inwardly as clearly shown in Fig. 2.. The perforations thus formed intersect the interior surface in practically a knife edge 30, so that any carbon or other deposit which may collect thereon quickly h-urnsand is blown oil due the explosions within the engine. Ilhe perforations are clear from any carbo deposit at the point where they enter the chamber 27, and by having. the entire portion 26 closed, it is impossible for the explosions of the engine to directly efilect of perforathe electrodes 20 and 23.

thus kept "ails The perforations 29 as shownin Figs. 1 to 3 inclusive are so positioned that when the plug is used as a vertical plug or has its axis in alinement with the axis of thepiston of the engine, they will not be in direct km with the explosion, and will not receive the first, impact of the explosion. However, whenI use my improved-plug'in a horizontal position or in any position in which the longitudinal axis extends at .an angle, to the axis of the piston, I preferably locate the perforations in the part 26 of the body pontion 1 as is shown at 31 in Figs. 1 and 5.

In all other-respects the construction of Figs. 1 and similar'toth'at disclosed in connection with Figs. 1 to 3 inclusive, .and I have therefore glven ti c parts the same reference numerals. f 1

As aconvenience, I preferably provide the screw 24 having the electrode 23 thereon, with a slot 32so that the electrode 23 4 may be adjusted toward or from the -elec-, trade 20. The chamber 27. is preferably made of large diameter so as to form a. large amount of clearance around the porcelain v 11 and electrodes 20 and 23. u 1

' By having the end 26 "losed and forming .a closurefor the lower part of the porcelain and the electrodes 20 and 23, practically no carbon is deposited upon said porcelain or electrodes, the perforations 29 providing ample opening for the ignition of the gases by the s ilark, so that the-entire interior of the cham er 27 is'kept clean. Furthermore, it is only the lighter portion of the gases which surrounds the body portion 1, and-therefore any carbon which forms a depositon thesurfaces forming the perforationsis quickly burnt and blown oif iand'the shoulder 4;."isfpreferably made an I gular so that the ja'oket 5 will properly seat itself without any chance of variation.v

The clearance w 'ch is. provided by the hole 19 in thenut- 1 allowsfor any irregu'larities'in the porcelain 11, so that the latterpraeticalIy is mounted in the jacket 5 and is-in realityi'suspended but firmly held therein. i x The body portionl may bemade ofany metalwhichfis a f ood conductor of elec- I 'tricity as may also e the electrodes 20 and j 23; *Furthermore, the jacket '5 may be made of inbtal or other suitable material, the porcela'i'n 1'1 "acting as an insulating member l 9 the electrode 2 In 'the: c1 'imsI have statedthat the hole '19' in the 'nut 16 is of larger cross section 7 than the insulating porcelain or member 11, Y but it will be -.understood that it .is only the portion of the insulating member 11 which asses through the'hole 19 whieh is of sma ler cross sectionthan the hole. and

:any of the other portions of the porcelain -'asabov'edescribed-. Furthermorapractically no'strain is placed. upon the porcelain 11,

such for example as the projection 10 may be of larger size than'the hole 19'and the porcelain 11 may be of an shape desired.

While I have'describe my invention as 1 taking a particulargform, itwill be understood that the various parts of my inven tion may be changed without departing from the spirit thereof, and hence I do not limit myself to the preciseconstruction set forth, butconsider that I am at liberty to make such changes and alterations as fairly come within the scope of. the appended claims. a Having thus described my invention, what I claim as new and desire .to secure go by Letters Patent is:

. 1. A spark plug comprising a hollow body portion closed atone end and having perforations adjacent snidend', electrodes pos1- tioned within said hollow, body portion, 35

means for-retaining the electrodes, said body portion having perforationsadjacent said closed end, said perforations being tapered inwardly to producecontinuous sharp edges, said edges being formed by the intersection ,90 of the perforations and the inner wall of the body portion, substantially as described. 2. A spark plug comprising a hollow body portion closed at one end and having perforations adjacent said end, electrodes posi- 9'5 tioned .within said hollowbody portion, means for retaining the electrodes,'said body portion having. perforations adjacent said closed end, said perforations being substantially elliptical. in shape and being tapered inwardly to produce continuous sharp edges at their pointsof intersection with the inner surface substantially as described,

3. A spark plug including a casing having of said body portion,

an opening terminating in a shoulder," a

jacket fitting saidopening and abutting said shoulder, said jacket having a hole through its inner end and aprecess of larger cross section than and intersecting said hole to provide a shoulder, an electrode-insulating member extending through said'hole, said member having a rojection resting on said shoulder of the jac et said recess extending to the opposite end of' of sufficient cross section throughout its en-' tire length to permit said projection to be free'to move into or out ofit, cement filling the space between said member and the inner wall of the recess, and means having a portion-in engag'ment with said jacket to impart thrust thereto iito firmly seat said jacketfagainst the shoulder in-the casing, said latter portion being free of the recess, substantially as described. I ,125

4. A spark plug includingacasing having an opening terminating in a shoulder, a jacket fittin said opening and abutting said I shoulder, said jacket having a hole through its inner end and a recess of larger cross l'eo the jacket andbeing 116 --inner wall of the recess,

section than and intersecting said hole to provide a shoulder, an electrode-insulating member extending through said hole, said member having a projection resting. on said shoulder of the jacket, said recess extending to the opposite end of the jacket and being of sufii'cient cross section throughout its entire length .to permit said projection to be free to move into or out of 1t, cement filling the space, between said member and the a nut having a threaded stem fitting said casing, said stem having-a portion in engagement with said jacket to impart thrust thereto to firmly seat said jacket against the shoulder in the easing, said latter portionbeing free of the recess, substantially-as described.

5. Aspark plug including'a casing having ,ian opening terminating in a shoulder, a

jacket fitting said opening and abutting said shoulder, said jacket having a hole through its inner end and a recess of larger cross sec-- tion than and intersecting said hole to pro vide a shoulder, an electrode-insulating member extending through said hole, said member having a projection resting on said shoulder of the jacket, said recess extending to the opposite end of the jacket and being ofsufiicient cross section throughout its entire length to permit said projection to be free to'move into or out of it, cement filling the space between said member and the inner Wall of the recess, a nut having a threaded stem fitting said casing, said stem havinga portion in engagement with said jacket to impart thrust thereto to firmly seat saidjacket against the shoulder in the casing, said latter portion being free of the .recess, said nut having an opening, said insulating member having an outwardly pro jecting portion extending through said opening and spaced therefrom, described. v

6. A spark plug including a casing having an opening terminating in a shoulder, a jacket-fitting said opening and abutting said shoulder, said jacket having a hole through its inner end and a recess of larger cross section than and intersecting said hole to provide a shoulder, an electrode-insulating substantially as member extending throu h said hole. ,said

acket to impart thrust thereto to firmly seat i said jacket against the shoulder in the easing, said latter portion being free of the recess, said nut'having an inwardly flared opening, said insulating member having an outwardly tapered portion extending through said flared opening and spaced therefrom, substantially as described.

7. A spark plug including a casing having an opening terminating in a shoulder, a

, jacket fitting said openin and abutting said shoulder, said jacket haying a hole through its inner end and a recess of larger cros's sectibnthan-ahd inters'cting said hole to provide'a shoulder, an Electrode-insulating member extending thro h said hole, said pro ection to be;

member having a projection resting on said shoulder of the jacket, sa d recess extending to the opposite end'of th jacket and being of suflicient cross section hroughout its enthe length to permit sai projectiolfto be free to move into or out oij it, cementfilling the space between said meniber and the inner wall of the recess, and me ins having a por: tion in engagement with s id jacket to impart thrust thereto to firml seat said jacket against the shoulder in the pa-sing, said latter portion being free of the recess, said means having an inwardly flared gopening, said insulating member havinl an outwardly tapered portion extending through said flared opening and spaced; therefrom, sub-1 stantially as described. I In testimony whereof have signed my name to this specification 'the presence of two subscribing witnesses};

WiLLiAMjs. THOMAS.

-Witnesses:.

C. R. ZIEGLER,{ CHAS. E. Porn. 

